/**
 * Copyright (c) 2008 - TheNittyGritty - Thomas Brekelmans
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package nl.thenittygritty.specification 
{
	import nl.thenittygritty.specification.AndSpecification;
	import nl.thenittygritty.specification.ISpecification;
	import nl.thenittygritty.specification.OrSpecification;	

	/**
	 * AbstractSpecification provides a default implementation for the and, or 
	 * and isGeneralizationOf method of ISpecification (which usually don't have 
	 * to be overriden).
	 */
	public class AbstractSpecification implements ISpecification 
	{
		/**
		 * Returns whether or not the given candidate is satisfied by the 
		 * current specification (i.e. passes all it's validation logic).
		 */
		public function isSatisfiedBy(candidate:*):Boolean
		{
			return null;
		}
		
		/**
		 * Creates a new specification which checks if the given candidate is 
		 * satisfied by this specification and the given specification.
		 */
		public function and(specification:ISpecification):ISpecification
		{
			return new AndSpecification(this, specification);
		}
		
		/**
		 * Creates a new specification which checks if the given candidate is 
		 * satisfied by this specification or the given specification.
		 */
		public function or(specification:ISpecification):ISpecification
		{
			return new OrSpecification(this, specification);
		}
		
		/**
		 * Checks if the given specification is a special case of the current 
		 * specification and thus if the current specification can be replaced 
		 * by the given specification.
		 * Checking is done by determining if the given specification is a 
		 * subclass of the current specification, override this method if a more 
		 * elegant way of checking is needed.
		 */
		public function isGeneralizationOf(specification:ISpecification):Boolean
		{
			var specificationClass:Object = specification as Object;
			return specificationClass.isPrototypeOf(this);
		}
		
		/**
		 * Returns the name of the class in a String.
		 */
		public function toString():String 
		{
			return "AbstractSpecification";
		}
	}
}
